Then go put it in the Feature Request forum and hope for upvotes...
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That request already exists I think:
I suggest stating your case there and upvoting the feature request.
Personally, I like the rPi solution as that also alows all sort of other devices to also see/share your media.
I think the problem is that you see it as you have Google Drive on your Shield, and really, that's not the case which is why Emby can't see it. Nothing is mounted... you just have an app that uses an API to interact with your Google drive. Currently there isn't a way to mount drive on an AndroidTV. So the best bet is to mount it on another system that supports it, and then share that.
You can at least "try" it with your system that you don't want to keep on all the time, and if that works, you can consider the rPi solution. It could sit quitely anywhere on your network. Hard to believe that there isn't a single network port available somehere, but that is also easy to fix.
I certainly get what you are going for though.